48 research outputs found
A summary of research relating to first grade reading, 1932-1963
Thesis (Ed.M.)--Boston UniversityProblem: An attempt to compare the rate of learning of colorful and abstract words of children in grade one.
Materials:
1. Thirty words were selected to be used in three groups of ten words each. Each list consisted of five colorful and five abstract words. Colorful words are those which have much meaning for children and abstract words are those with little meaning. The words were printed on 3 x 11 inch flash cards in lower case letters.
2. Check sheets were made with spaces for checking the retention of words at three different times and pictures were made to enrich the colorful words.
3. Directions were prepared and given to each teacher who participated in the study.
4. Kuhlmann-Anderson Intelligence Test: Battery A.
5. Detroit Word Recognition Test: Form A [TRUNCATED
Radio Observations of the Hubble Deep Field South Region III: The 2.5, 5.2 and 8.7 GHz Catalogues and Radio Source Properties
Deep radio observations of a wide region centred on the Hubble Deep Field
South have been performed, providing one of the most sensitive set of radio
observations acquired on the Australia Telescope Compact Array to date. A
central rms of ~10 microJy is reached at four frequencies (1.4, 2.5, 5.2 and
8.7 GHz). In this paper the full source catalogues from the 2.5, 5.2 and 8.7
GHz observations are presented to complement Paper II, along with a detailed
analysis of image quality and noise. We produce a consolidated catalogue by
matching sources across all four frequencies of our survey. Radio spectral
indices are used to investigate the nature of the radio sources and identify a
number of sources with flat or inverted radio spectra, which indicates AGN
activity. We also find several other interesting sources, including a broadline
emitting radio galaxy, a giant radio galaxy and three Gigahertz Peaked Spectrum
sources.Comment: Accepted by AJ. 13 figures and 13 table
Radio Observations of the Hubble Deep Field South region: I. Survey Description and Initial Results
This paper is the first of a series describing the results of the Australia
Telescope Hubble Deep Field South (ATHDFS) radio survey. The survey was
conducted at four wavelengths - 20, 11, 6, and 3 cm, over a 4-year period, and
achieves an rms sensitivity of about 10 microJy at each wavelength. We describe
the observations and data reduction processes, and present data on radio
sources close to the centre of the HDF-S. We discuss in detail the properties
of a subset of these sources. The sources include both starburst galaxies and
galaxies powered by an active galactic nucleus, and range in redshift from 0.1
to 2.2. Some of them are characterised by unusually high radio-to-optical
luminosities, presumably caused by dust extinction.Comment: Accepted by AJ. 32 pages, 4 tables, 3 figures. PDF with
full-resolution figures is on
http://www.atnf.csiro.au/people/rnorris/N197.pd
Radio Observations of the Hubble Deep Field South Region II: The 1.4 GHz Catalogue and Source Counts
This paper is part of a series describing the results from the Australia
Telescope Hubble Deep Field South (ATHDFS) survey obtained with the Australia
Telescope Compact Array (ATCA). This survey consists of observations at 1.4,
2.5, 5.2 and 8.7 GHz, all centred on the Hubble Deep Field South.
Here we present the first results from the extended observing campaign at 1.4
GHz. A total of 466 sources have been catalogued to a local sensitivity of 5
sigma (11 microJy rms). A source extraction technique is developed which: 1)
successfully excludes spurious sources from the final source catalogues, and 2)
accounts for the non-uniform noise in our image. A source catalogue is
presented and the general properties of the 1.4 GHz image are discussed. We
also present source counts derived from our ATHDFS 1.4 GHz catalogue.
Particular attention is made to ensure the counts are corrected for survey
incompleteness and systematic effects. Our counts are consistent with other
surveys (e.g. ATESP, VIRMOS, and Phoenix Deep Field), and we find, in common
with these surveys, that the HDFN counts are systematically lower.Comment: Accepted by AJ. 51 pages, 21 figures, 2 table
Deep ATLAS radio observations of the CDFS-SWIRE field
We present the first results from the Australia Telescope Large Area Survey
(ATLAS), which consist of deep radio observations of a 3.7 square degree field
surrounding the Chandra Deep Field South, largely coincident with the infrared
Spitzer Wide-Area Extragalactic (SWIRE) Survey. We also list
cross-identifications to infrared and optical photometry data from SWIRE, and
ground-based optical spectroscopy. A total of 784 radio components are
identified, corresponding to 726 distinct radio sources, nearly all of which
are identified with SWIRE sources. Of the radio sources with measured
redshifts, most lie in the redshift range 0.5-2, and include both star-forming
galaxies and active galactic nuclei (AGN). We identify a rare population of
infrared-faint radio sources which are bright at radio wavelengths but are not
seen in the available optical, infrared, or X-ray data. Such rare classes of
sources can only be discovered in wide, deep surveys such as this.Comment: Accepted by A
A panchromatic study of BLAST counterparts: total star-formation rate, morphology, AGN fraction and stellar mass
We carry out a multi-wavelength study of individual galaxies detected by the
Balloon-borne Large Aperture Submillimeter Telescope (BLAST) and identified at
other wavelengths, using data spanning the radio to the ultraviolet (UV). We
develop a Monte Carlo method to account for flux boosting, source blending, and
correlations among bands, which we use to derive deboosted far-infrared (FIR)
luminosities for our sample. We estimate total star-formation rates for BLAST
counterparts with z < 0.9 by combining their FIR and UV luminosities. Star
formation is heavily obscured at L_FIR > 10^11 L_sun, z > 0.5, but the
contribution from unobscured starlight cannot be neglected at L_FIR < 10^11
L_sun, z < 0.25. We assess that about 20% of the galaxies in our sample show
indication of a type-1 active galactic nucleus (AGN), but their submillimeter
emission is mainly due to star formation in the host galaxy. We compute stellar
masses for a subset of 92 BLAST counterparts; these are relatively massive
objects, with a median mass of ~10^11 M_sun, which seem to link the 24um and
SCUBA populations, in terms of both stellar mass and star-formation activity.
The bulk of the BLAST counterparts at z<1 appear to be run-of-the-mill
star-forming galaxies, typically spiral in shape, with intermediate stellar
masses and practically constant specific star-formation rates. On the other
hand, the high-z tail of the BLAST counterparts significantly overlaps with the
SCUBA population, in terms of both star-formation rates and stellar masses,
with observed trends of specific star-formation rate that support strong
evolution and downsizing.Comment: Accepted for publication in the Astrophysical Journal. 44 pages, 11
figures. The SED template for the derivation of L_FIR has changed (added new
figure) and the discussion on the stellar masses has been improved. The
complete set of full-color postage-stamps can be found at
http://blastexperiment.info/results_images/moncelsi
Patient emergency health-care use before hospital admission for COVID-19 and long-term outcomes in Scotland: a national cohort study
BackgroundIt is unclear what effect the pattern of health-care use before admission to hospital with COVID-19 (index admission) has on the long-term outcomes for patients. We sought to describe mortality and emergency readmission to hospital after discharge following the index admission (index discharge), and to assess associations between these outcomes and patterns of health-care use before such admissions.MethodsWe did a national, retrospective, complete cohort study by extracting data from several national databases and linking the databases for all adult patients admitted to hospital in Scotland with COVID-19. We used latent class trajectory modelling to identify distinct clusters of patients on the basis of their emergency admissions to hospital in the 2 years before the index admission. The primary outcomes were mortality and emergency readmission up to 1 year after index admission. We used multivariable regression models to explore associations between these outcomes and patient demographics, vaccination status, level of care received in hospital, and previous emergency hospital use.FindingsBetween March 1, 2020, and Oct 25, 2021, 33 580 patients were admitted to hospital with COVID-19 in Scotland. Overall, the Kaplan-Meier estimate of mortality within 1 year of index admission was 29·6% (95% CI 29·1-30·2). The cumulative incidence of emergency hospital readmission within 30 days of index discharge was 14·4% (95% CI 14·0-14·8), with the number increasing to 35·6% (34·9-36·3) patients at 1 year. Among the 33 580 patients, we identified four distinct patterns of previous emergency hospital use: no admissions (n=18 772 [55·9%]); minimal admissions (n=12 057 [35·9%]); recently high admissions (n=1931 [5·8%]), and persistently high admissions (n=820 [2·4%]). Patients with recently or persistently high admissions were older, more multimorbid, and more likely to have hospital-acquired COVID-19 than patients with no or minimal admissions. People in the minimal, recently high, and persistently high admissions groups had an increased risk of mortality and hospital readmission compared with those in the no admissions group. Compared with the no admissions group, mortality was highest in the recently high admissions group (post-hospital mortality HR 2·70 [95% CI 2·35-2·81]; pInterpretationLong-term mortality and readmission rates for patients hospitalised with COVID-19 were high; within 1 year, one in three patients had died and a third had been readmitted as an emergency. Patterns of hospital use before index admission were strongly predictive of mortality and readmission risk, independent of age, pre-existing comorbidities, and COVID-19 vaccination status. This increasingly precise identification of individuals at high risk of poor outcomes from COVID-19 will enable targeted support.FundingChief Scientist Office Scotland, UK National Institute for Health Research, and UK Research and Innovation
The Detection of an Extremely Bright Fast Radio Burst in a Phased Array Feed Survey
We report the detection of an ultra-bright fast radio burst FRB)from a modest, 3.4-day pilot survey with the Australian Square Kilometre Array Pathfinder. The survey was conducted in a wide- field fly’s-eye configuration using the phased-array-feed technology deployed on the array to instantaneously observe an effective area of 160 deg2, and achieve an exposure totalling 13200 deg2 hr. We constrain the position of FRB 170107 to a region 8 ́ x 8 ́ in size(90% containment)and its fluence to be 58 ± 6 Jy ms. The spectrum of the burst shows a sharp cutoff above 1400 MHz, which could be due to either scintillation or an intrinsic feature of the burst. This confirms the existence of an ultra-bright (> 20 Jy ms) population of FRBs
Radio and mid-infrared identification of BLAST source counterparts in the Chandra Deep Field South
We have identified radio and/or mid-infrared counterparts to 198 out of 350
sources detected at >=5 sigma over ~ 9 square degrees centered on the Chandra
Deep Field South (CDFS) by the Balloon-borne Large Aperture Submillimeter
Telescope (BLAST) at 250, 350 and 500 um. We have matched 114 of these
counterparts to optical sources with previously derived photometric redshifts
and fitted SEDs to the BLAST fluxes and fluxes at 70 and 160 um acquired with
the Spitzer Space Telescope. In this way, we have constrained dust
temperatures, total far-infrared/sub-millimeter luminosities and star formation
rates for each source. Our findings show that on average, the BLAST sources lie
at significantly lower redshifts and have significantly lower rest-frame dust
temperatures compared to submm sources detected in surveys conducted at 850 um.
We demonstrate that an apparent increase in dust temperature with redshift in
our sample arises as a result of selection effects. Finally, we provide the
full multi-wavelength catalog of >= 5 sigma BLAST sources contained within the
complete ~ 9 square degree survey area.Comment: Published in the Astrophysical Journal: 2009, ApJ, 703, 285. 23
pages, 13 figures. Data available at http://blastexperiment.inf